Activity at Klyuchevskoy volcano in Kamchatka, Russia increased significantly on October 31, 2023, prompting KVERT to raise the Aviation Color Code from Orange to Red. The ash column reached up to 9.8 km (32 152 feet) above sea level and extended for 365 km (226 miles) to the SSE of the volcano.
Seismic activity at Mount Anak Krakatau intensified on October 28, 2023, prompting Indonesian authorities to issue a 5 km (3.1 miles) exclusion zone around the main crater. The heightened activity included a range of earthquakes and internal vibrations indicative of potential eruptions.
An episode of complex volcano-tectonic unrest is currently affecting the Reykjanes Peninsula, the Icelandic Met Office (IMO) said on October 29, 2023. It is interpreted to result from multiple deformation sources at depth, which are interacting and affecting a wide area across the peninsula.
An explosive-effusive eruption continues at the Klyuchevskoi volcano in Kamchatka, Russia, on October 29, 2023, with ash clouds reaching a height of 10 km (33 000 feet) above sea level. The Aviation Color Code remains at Orange.
On October 25, 2023, Colombia’s Puracé Volcano experienced a noticeable increase in seismic activity, with earthquakes reaching a maximum magnitude of 1.0. Located between 1 and 4 km (0.6 – 2.5 miles) in depth, these quakes coincided with higher degassing levels and persistent high CO2 values.
New activity/unrest was reported for 5 from October 18 to 24, 2023. During the same period, ongoing activity was reported for 16 volcanoes.
An intense earthquake swarm started north of Grindavik and near Fagradalsfjall volcano, Iceland’s Reykjanes Peninsula early on October 25, 2023, prompting the Civil Protection Service to declare an uncertainty phase due to the seismic swarm.
On October 25, 2023, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) raised the alert status of Bulusan Volcano from Alert Level 0 to Alert Level 1 due to a period of low-level unrest that began on October 14, 2023. This includes a series of 121 volcanic earthquakes and signs of ground deformation.
Increased seismic activity has been recorded at Bogoslof volcano in Alaska since October 21, 2023, leading authorities to raise the alert level.
The Philippine Institute of Volcanology and Seismology reported a significant rise in both seismic activity and lava effusion at Mayon Volcano on October 21, 2023.